1. Field of the Invention
This invention relates to automobile protective systems, namely side curtain type airbags and the manner in which individual airbags are folded together and stored prior to use.
2. Description of Related Art
Air bags are commonly used safety devices in automobiles and other fast moving passenger vehicles. Commonly, air bags are provided to protect against head on collisions. Side impact air bag protection is now becoming a more common accessory in vehicles. Curtain type air bags, used to protect against side impacts, typically have a greater surface area than front impact type airbags, thus, rolling, packing and storing curtain type air bags is challenging. Adding to the challenge of storing curtain air bags is the limited amount of free space above the doors on the vehicle's roofline and, in general, above the roofliner. The air bag equipment, further, must be isolated from other wiring and drainage devices when located in common areas. Additionally, the air bag must be hidden when not deployed while still being effectively deployable.
U.S. Pat. No. 6,371,512 to Asano et al. describes a typical side curtain air bag. Referring to FIGS. 10A and 10B of the Asano et al. patent, reproduced herein as prior art FIGS. 1a and 1b, one method of storing an uninflated curtain air bag is illustrated with the leftmost portion being located toward the vehicle inside (indicated as “inboard side”). A turned back portion 116G contacts a length of the air bag located directly above the turned back portion 116G. These two portions, in combination referred to as a rolled-up portion, are rolled by first bringing the lowest end of the rolled-up portion toward the inside of the vehicle. The lowest end is then curled until it is completely enclosed by the remainder of the rolled-up portion. The curled portions are then simply rolled upward causing the remainder of the rolled-up portion to curl around the exterior of the portion being rolled. An upper section, located directly above the rolled-up portion is collapsed in a pleated manner. The rolled-up portion is often repositioned so that the upper pleated section is substantially covered with the rolled-up portion.
One drawback to the configuration of the prior art, where the rolled-up portion is rolled toward the inside of the vehicle, is the magnitude and direction of force generated upon the actuation of the air bag system. As the air bag fills with air and the air bag unrolls, upon each revolution, the remaining rolled portion is forced toward the inside of the vehicle and through the vehicle's roofliner and garnish. This sometimes results in an occupant of the vehicle being contacted by the air bag while the air bag is deploying and risks injury to the vehicle occupant. Additionally, excessive force is generated against the roofliner and garnish. Although some is required force to dislodge the roofliner from a position overlapping the garnish, often excess force fractures the garnish which can further injure the vehicle occupant. Replacement of the garnish is also, then required.
What is desired is an air bag that can be deployed using less force directed to the inside of the vehicle than what is used in the existing art and which will not create injury concerns for vehicle occupants.